1. Field of the Invention
The present invention pertains to a wireless system for remotely activating a data link to remote devices in a self-powered fashion. In a primary embodiment, the invention is directed for use with an armament system with a plurality of munitions which require pre-conditioning initialization prior to launch, but which have no direct wire umbilical connection to the host platform. The invention is also generally applicable to any situation where it is desired to activate a data link to remote devices without requiring the use of any standby power source within the remote devices while simultaneously not requiring any physical connection to the remote devices.
2. Description of the Related Art
Today's weapons systems increasingly rely on the use of precision guided munitions (PGM's) to improve the accuracy with which ordnance may be delivered to a target, thereby increasing the damage expectancy for each weapon, and reducing the number of weapons and delivery platforms which must be utilized to achieve the desired level of damage. Reducing the number of weapons and sorties which must be committed to achieve a desired damage expectancy result minimizes crew exposure to enemy defenses and offers the potential for substantially reduced munitions and operations costs.
Today's PGM's require varying degrees of prelaunch preparation, or initialization, to enable and prepare the PGM's guidance system, and control targeting and launch sequencing. This is generally accomplished with a data link between the host platform and the munitions, most commonly over a hardwire umbilical between the host platform and the PGM. A hardwire connection affords the ability to uniquely and individually communicate between the host platform and each munition and provide a source of power to sustain the communication process.
Recent innovations to reduce the cost of upgrading host platforms to interface with PGM's have resulted in the elimination of the hardwire umbilical to PGM's, using instead a wireless interface and self-contained munitions power. Current implementations of the wireless interface require that the munitions contain a standby power source, viz., a standby battery, to maintain a low-power operational mode of the receive data link as the munitions await for instructions specifically directed to itself. Such battery-powered implementations provide a relatively short (on the order of days) period of standby operation before the standby datalink battery needs to be replaced.
Prior art teaches methods to supply power for data link operation. U.S. Pat. No. 4,091,734, issued to Maisonneuve, et al. involves employment of fiber-optic connections to remotely located electrical apparatus to supply sufficient power for data link operation. Others might use large photovoltaic optical (sunlight) power collection arrays, to supply sufficient power for data link operation.
U.S. Pat. No. 4,091,734, issued to Redmond, et al. teaches using power from a photovoltaic cell stimulated by a visible light source to power an optical receiver datalink. Though Redmond's teaching and implementation might be used for a light-activated control function, its range is limited to 20 inches, which is insufficient for remote (i.e., longer range) light activation control applications. Redmond, et al. teach the use of a direct IR carrier modulation which utilizes a modulation of the raw IR energy, i.e., 940 manometers wavelength, for transmission of single information bits, then relying on a protocol to encode information, in Redmond's case using a pulse numbers protocol. The Redmond, et al. approach can implement ranges only up to 20 inches (1.6 ft). This is not sufficient for some intended wireless interface applications (8 ft). It is the intent of the current invention to overcome such restrictive range limitations.
The modulation method employed by Redmond cannot, with any practical scaling or extension, meet many wireless interface range requirements. In particular, practical "scaled up" version of Redmond's techniques can feasibly achieve the required virtual umbilical range for dispersed munitions in an aircraft environment activation.